Articulator for prosthetic dentistry



y 1959 v. BONFANTI 2,884,696

ARTICULATOR FOR PROSTHETIC DENTISTRY Filed April 18, 1955 INVENTOR.

Wdmd 5. SW TM/ aet- United States Patent G ARTICULATOR FOR PROSTHETIC DENTISTRY Vittorio Bonfanti, Milan, Italy Application April 18, 1955, Se'rial No. 502,099 Claims priority, application Italy April 22, 1954 Claims. (Cll 32-32) This invention relates to articulators for prosthetic dentistry and, more particularly, it is related to a new and improved device of the type currently defined as articulators by those skilled in the art to which this invention appertains, and designed to support the models obtained from the impression of the patients oral cavity for construction, setting, adjusting and checking of prosthetic dentistry work, or dentures, partial or complete, upper or lower ones.

It is known that a plurality of different articulators have been devised to make possible and to improve the performance of such dental prosthetic Work. Some of said articulators consist of plain hinge devices wherein the models are supported by upper and lower bow members relatively connected by means of a plain pivotal connection, the axis thereof is positioned in respect to said models to nearly correspond to the average axis of the temporo-mandibular articulations during the chewing movements or masticatory function of the dentures.

Other more advanced articulators, the so-called anatomic articulators, comprise pin and-slot sliding and pivotal connecting means, or equivalent means designed for having the upper bow member movable with respect to the lower one either rotatably and slidably along a predetermined inclined plane, spatially positioned in respect to the models'and the dentures supported thereon to nearly correspond to the mandibular glide, or actual anatomic lateral and protusive movements of the mandible while the teeth remain in functional contact, and determined solely by the temporo-mandibular articulation and the occlusal or incisal surfaces of the teeth, and by the muscles and ligaments of said articulation, while the free movements of the mandible where there is no tooth contact correspond to the raising of said upper bow member about the axis of the hinge connecting means of the device.

In the articulators of current construction, the upper bow member is supported by a three-point bearing system, comprising two rear and laterally spaced bearing points formed, in general, by hinging means of the pinand-slot type, and a front bearing point formed by an incisal pin, ie by an adjustable rod member vertically arranged and having a lower end portion resting on an inclined plane.

The various articulators heretofore constructed are sub ject to several serious objections. But for the plain hinge articulators of cheap manufacture, which cannot produce prosthetic occlusions of the desirable accuracy, such devices are costly and rather complicated consisting of a great number of metallic parts. The upper and lower bow members of said articulators are hingedly and removably interconnected by rather complex means comprising pivots, slotted members, spring means and releasing means, subject to wear and to damage by shocksand stresses. Full separation of said members requires some handling of the said releasing means and compression of spring means.

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The operation of said known articulators is also subject to several objections. Due to the fact that no rigid connection is allowed between the upper and lower bow members of the 'articulator (which might impair the prosthetic work if not exactly set and adjusted), the upper bow member of articulators of the prior art simply rests, by its own weight only, on the incisal pin.v Said incisal pin, which is arranged in the fore portion of the device, hinders the full observation and adjustment of the work. The slightly improper contacts between the occlusal or incisal surfaces of upper and of lower dentures during the mandibular guide cannot be detected for the bestadjustment of the prosthetic work. Further, while the most advanced types of anatomic articulators heretofore known allow relative movements between the bow members thereof, which accurately correspond to the mandibular glide due to the condylar path in the actual anatomic structure of the skull bones comprising the temporo-mandibular articulation, the members cannot be relatively set in any desired position comprised in said path, but only in a predetermined average one. Any improper occlusive condition which may occur in any position comprised in said condylar path, except for said average one, is therefore diflicult to detect and to provide for the desired adjustment of the prosthetic appliance.

Having the above said and other conditions and objections in mind, it is a general object of this invention to provide a new and improved articulator for prosthetic dentistry, which is not subject to said objections and which comprises certain new and greatly advantageous features,

, fully described in the specification and drawings and defined in and by the appended claims, that make my new articulator particularly adapted to the most accurate workmanship of prosthetic appliances, to the checking, to the repairing and to the adjusting of same, to clearly and readily explain either to those skilled in the art of dentistry and also to those not skilled, like for instance the patients, the actual construction and operation of the dentures produced, and the proper functional setting of the opposite and co-operating teeth in any position possible by the mandibular glide.

A more specific object of this invention is to provide a new and improved 'articulator for prosthetic dentistry comprising an upper bow member, a lower bow member and magnetic means connected to said members and adapted to magnetically and removably connect said members in their desired relative arrangement, for having the said members properly set and maintained in the occlusive relationship of the dentures supported thereby and for having same fully detached by simply applying a force by hand, directed to raise the upper bow member and enough for having said magnetic means spaced.

Another object of this invention is to provide an articulator as referred to above, wherein the said magnetic means are constructed in form of permanent magnets, connected to the said upper and lower bow members, having opposite fiat polar surfaces, adapted to be juxtaposed and to relatively contact in magnetic connection as the said bow members are relatively set in occlusive relationship, the surfaces being spatially arranged in the plane comprising the actual condylar path, so that the upper and lower bow members may be relatively moved along said plane, performing relative movements corresponding to the mandibular glide, while the magnetic means, sliding on the said contacting flat surfaces thereof, remain in magnetic connection and the prosthetic appliances teeth remm'n in functional contact, and so that the said how members may be kept, without any blocking, or looking or other operation, in any desired relative position comprised within the said condylar path.

A further object of this invention is to provide a new and improved articulator for prosthetic dentistry comprising an upper bow member, a lower bow member, and parts made integral with said members, having co-operating portions adapted to confine the relative movements of the said members, corresponding to the mandibular glide, within the anatomic limits of the condylar path, wherein the said portions are shaped and arranged as anatomic models, to represent the true temporo-mandibular articulation both in its construction in the skulls bones and in its operation during the said mandibular glide, which is confined by the skulls bones structure of the said temporo-mandibular articulations, ie by the limits of possible movements of the condyle in the glenoid fossa. 1

A still further object of this invention is to provide a new and improved articulator having an upper bow member, a lower bow member, means for detachably connecting said members in at least average occlusive condition of properly constructed prosthetic appliances supported thereby, and means for detachably connecting to said upper and to said lower bow members an upper and respectively a lower model adapted to shape and to support respectively the upper and the lower prosthetic appliance, wherein the said lower model may be substituted by an additive member, adapted to be removably connected to said lower bow member and provided with an up-facing flat surface, actuating an incisal table whereon the upper prosthetic appliances teeth may be initially aligned and set, the said fiat surface being in turn provided with longitudinal and transversal lines defining the sagittal centric line of the dental apparatus and respectively defining the fore point of the Bonwills triangle, the fore vertex of which is defined by the intercrossing of said lines and the rear vertexes of which correspond to the temporo-mandibular articulations.

A still further object of this invention is to provide a new and improved articulator for prosthetic dentistry, of the type referred to above, comprising upper and lower bow members connected with end portions shaped to effectively and operatively represent the glenoid fossa and respectively the condyle and the skulls bone portions near to the temporo-mandibular articulation, wherein each one of said members comprising the respectively shaped end portion is constructed in one shaped piece of plastic material, and preferably of transparent plastic material, like F.I. Plexiglas to allow for full observation of the prosthetic appliances under construction, adjustment and checking and of the relative position of the condyle in the co-operating glenoid fossa, in the various positions comprised in the mandibular glide.

In the proceeding general analysis of my invention, in the detailed description and in the appended claims reference is and will be made to several anatomic expressions and definitions for better understanding of my invention. A full knowledge of the matter involved in this disclosure and which may be of interest for understanding the invention may be had by perusing of any modern text-book relating to Prosthetic Dentistry in general. Useful considerations about the use of articulators and the importance of correct teeth contacting relationship in the various positions admitted by the mandibular glide may be found, for example, in volume 38, number 6, June 1949 of The Journal of the American Dental Association, from page 697 (The Accuracy and Practical Value of Records of Condyle Path Inclination, essay by F. W. Craddock).

The generic and specific objects of this my invention, together with these and other important features and advantages thereof will become apparent as the description proceeds, and will be more fully understood by a consideration of the following detailed disclosure of a preferred form of embodiment of the invention, as embodied in an articulator for prosthetic dentistry, of the fixed average anatomic type, reference being made to the accompanying drawings, forming an essential component of the disclosure, and wherein:

Fig. 1 is a somewhat simplified perspective view of the said preferred form of embodiment of the invention, wherein the lower bow member of the articulator is provided with an incisal table;

Fig. 2 is an exploded side view of the various components of the articulator, of an upper model, of a lower model supporting a lower prosthetic appliance, like a complete lower denture, and of a wax record or impression of the upper oral cavity (said wax record being shown in vertical sectional view) adapted to be com pared with the said incisal table (diagrammatically shown in dot-and-dash lines). I

Fig. 3 is side elevation of said incisal table additive member; 1

Fig. 4 is a top view of the articulator, with part of its upper bow member broken away to show partly the lower bow member arranged thereunder;

Fig. 5 is a bottom view of the upper bow member of the articulator, and

Fig. 6 is a vertical sectional view of the articulator arranged in occlusive condition, and taken along the line 66 of Fig. 4.

Identical reference numerals refer to identical parts, members and portions thereof throughout the several figures of the accompanying drawing. Further, in the fol lowing detailed description referred to the accompanying drawing any indication referring to a position and/or to a direction, say fore, rear, upper, lower, and so on, will correspond to the actual position and/or direction related to dentures actually set in the patients oral cavity, which is reproduced in its occlusive condition and partly in its shape by the articulator, while the dental apparatus is represented by the prosthetic appliances set on and supported by same.

In the accompanying drawings the articulator produced according the said preferred form of embodiment of the invention is provided with an upper bow member and with a lower bow member, the said members being indicated in general by numeral 10 and respectively by numeral 11. The said upper member 10 consists mainly of a shaped block made from one piece of plastic, comprising a substantially flat principal portion 12, having a rounded fore end portion 13 and a wider straight rear side portion 14. Said principal portion 12 is made integral with two curved and shaped extensions 15, rearwardly and sidewardly extended from the side end portions of said rear side 14 in symmetrical shape and arrangement, and having enlarged end portions 16 provided with downwardly facing shaped cavities 17 as shown in Figs. 5 and 6.

Said extensions comprising the shaped portions 15 and 16 are anatomically modelled to simulate the actual skulls bones comprising the glenoid fossa reproduced substantially in the true shape and arrangement thereof, while the said shaped cavities 17 are formed to accu rately reproduce said glenoid fossa, in its precise average shape, dimension and spatial arrangement in an average human skull, the upper edentation of which is represented by the upper prosthetic appliance set on the said upper member 10 below its principal portion 12, as fully explained below.

The principal substantially fiat portion 12 of upper member 10 is provided with a down-facing recess 18 (Figs. 5 and 6) wherein a correspondingly shaped dome portion 19 (Fig. 2) of an upper model 20 of the patients oral cavity may precisely fit and be firmly connected, for example by means of a screw 21 (Figs. 2, 4, 5 and 6) traversing the flat principal portion 12 and provided with a knurled knob forming an enlarged outer head 22, adapted for easy hand-drivingof said screw on into or oif said model 20.

The lower bow member 11 likewise mainly consists forming I of a one-piece block made of plastic and includes a principal substantially flat portion 30 substantially symmetrical to the principal portion 12 of the above de-.

scribed upper bow member 10, and a rounded foreend portion 31. Said principal portion 30 is made integral with two, symmetrical extensions 32, upwardly and side'- wardly extended from the rear corners of said portion 30, and having shaped upper end portions 33. Said extensions 32 and the said upper end portions'33 thereof are anatomically modelled for reproducing in a true average shape, dimension and arrangement of the side rear portions of the actual osseous frame structure of an human mandible, wherein the condyle is reproduced by the said shaped upper end portions 33 in its precise shape and arrangement in the mandible, the lower edentationof which is represented by a lower prosthetic appliance, properly constructed and set on said lower member 11 above its said principal portionSG.

The said principal portion 30 is provided at its upper face with an up-facing recess 35 (Figs. 4 and 6), which is somewhat symmetrical in shape, arrangement and in its operation to the said recess 18'of upper member 10, and wherein a dome shaped bottom portion36 (Fig; 2) of a lower model 37 of the patients oral cavity, designed for shaping, adjusting and supporting an adapted lower prosthetic appliance 58, may precisely fit and be firmly connected to said lower bow member 11. A screw 38 (Figs. 2 and 6) traversing said principal portion 39 and provided with a knurled knot forming an enlarged head 39 may be provided for having said model 37 detachably secured to said lower member 11 above its principal portion 30.

In the form of embodiment shown, the articulator according to the invention is further provided with an additive member shown in Fig. 3 and, set on the articulator, in Figs. 1 and 6. Said additive member comprises a base portion 40 having a dome shaped bottom end portion 41 shaped to precisely fit inside of'the said up-facing recess 35 of the lower bow member 11, as shown in Fig. 6. The same screw 38 maybe used for having the said additive member detachably secured to the lower member 11 above the principal portion 30 thereof, in the manner above described, relating to securing of the lower model 37. The additive member may be constructed of plastic material, for instance of plexiglass, and a metallic tubular member 42 (Fig. 6) with female screw thread may be cast into the plastic material to provide a screw connection with screw 38.

Said additive member comprises further a plate shaped upper portion 43, having an horizontal plain upper surface arranged to actuate the plane of occlusion, i.e. the average plane on which teeth of upper and of lower edentations, formed either by natural teeth or by prosthetic appliances, are set in occlusive correctly centric contacting relationship. The upper portion. 43 of the described additive member of my articulator therefore actuates an incisal table on which the teeth of the upper prosthetic appliance may be properlyv set, while the teeth of the lower appliance may be successively set in proper position and alignment by comparing same to the previously set teeth of the upper appliance.

As shown in Fig. 2, the provision of the incisal table in an articulator produced according to this invention may be advantageously used for adjustment of the upper model 20 with respect to the theoretical plane of occlusion, the effective position of which is strictly related to the position of the temporo-mandibular articulation. Provided that the upper surface of plate portion 43 of the described additive member may be secured in one predetermined position with respect to the lower bow member 11 of the articulator, i.e. with respect to the portions 33 of the latter member, representing the condyle, said upper surface of portion 43 may be adapted to effectively represent the said theoretical plane ofocclusion. A primary impression 45 made of wax, alginate or modeling compound may bev provided and adjusted to set the height, orvertical thickness of its material below the patients endentulous mucosa (which 6 isreproduced' by the shape oflbwerportibn of 'upper model 20) at the value corresponding to the desired spacing between the mucosa and the plane of occlusion, i.e. to the spacing that the prosthetic appliance must occupy. By modeling and adjusting the upper portion 19 of the upper model 20 until the mucosa reproducing lower portion 47 of the'model properly fits inside the primary impression and until the lower surfaces of said impression properly and fully rest on the upper surface of portion 43 of additive member, while the two bow members ofthe articulator are relatively set and kept in occlusive position (as it will be disclosed below), it will be readily possible" to set the several members described for producing a proper prosthetic upper appliance which may fit'in said model 20 and which will properly occlude, i.e. enter in functional contact with the lower natural or prosthetic teeth, in the true theoretical plane of occlusion.

For an easier and more accurate setting of the prosthetic appliances under construction, the upper surface of plate portion 43 of the additive member is provided with a longitudinal line 44 (Fig. l) and with a transversal or cross line 46, neatly drawn on said surface, by engraving for example, and so positioned on said surface that the point at which the said lines 44 and 46 intersect correspond to the fore vertex of the Bonwills triangle, the rear vertexes of which are set on the condyles, actuated by the described upper end portions 33 of the lower bow member lls rear extensions 32, as above described.

A study of Fig. 1, wherein a typical upper prosthetic appliance is shown in dashed lines and diagrammatically out-lined, will readily make apparent. to those skilled in the art how the application of the described additive member may advantageously be used for setting the appliance in the most desirable centric relationship with the anatomic features defined by the triangle of Bonwill, i.e. with the actual osseous frame structure of the maxilla, said proper setting of the upper appliance being in turn usefully exploited for accurately setting the teeth of the lower prosthetic appliance, if any, in proper functional contacting relationship with the upper teeth, in said plane of occlusion and in the same centric relationship with the triangle of Bonwill, i.e. with the actual osseous frame structure of the mandibular apparatus.

As outlined in the preamble of this disclosure, in an articulator for prosthetic dentistry, produced according to a preferred form of embodiment of my invention, the upper bow member thereof is detachably connected to the lower one (and vice-versa) by magnetic means in and at any position admitted by the mandibular glide.

In the form of embodiment shown in the accompanying drawing and particularly in Figs. 2 and 4-6, the said magnetic means consist of two permanent magnets, of for instance an aluminium-nickel-cobalt alloy, according to current knowledge of the art, oneof said magnets beingv connected to one bow member and the other one to the other bowmember of the articulator and arranged to remain in stable contacting relationship and in mag.- netic connection, as said two bow members are set in any relative position of, occlusive condition of prosthetic appliances supported thereby.

As shown in said Figs. 2 and 4-6,. a rod-shaped permanent magnet 50, having a plain lower face 51 (Figs. 2, 5 and 6), is firmly secured to the upper member 10, and preferably partially embedded in the material forming the principal portion 12, near and parallel to the rear straight side 14 thereof. A substantially similar rod-shaped other permanent magnet 52, having a plain upper face 53 (Figs. 2', 4 and 6) is likewise firmly secured to the lower member 11, and preferably partially embedded in a bridge portion 34 arranged between and made integral at its ends with the upper portions of said upraised extensions. 32. The surfaces 51 and 53 of magnets and 52', respectively, are carefully levelled and made smooth for having any one of said magnets easily slidable on the other, when said magnets are in contact and magnetically connected. i

As it will be readily understood from the Several figures of the accompanying drawing, and in particular from Fig. 6, the illustrated form of embodiment of my improved articulator appertains to the class of the so-called fixed average anatomic articulators, wherein the two bow members of the articulator are interconnected by means which allow a relative movement of said members with respect to each other on but one predetermined inclined plane corresponding to the average inclination of the human mandibular glide. In the very most of the cases of practical application of prosthetic dentistry it has been found that the inclination of 30 in respect to the plane of occlusion is acceptable for producing a prosthetic occlusion of great accuracy.

As shown in Fig. 6, the permanent magnets 52 and 50 are set and firmly connected to the said members 11 and 10 respectively, at such inclined arrangement that the plain, levelled and smooth surfaces 53 and 51, respectively, actuate both a portion of a plane at 30 with respect to the occlusion plane defined by the upper surface of the described additive member 40-43, when applied and secured to the lower member 11. Further, the said magnets are relatively positioned in relative polar opposition, so that they tend to contact and to mutually adhere on said surfaces, causing the said bow members 10 and 11 to be brought and kept in a mechanical-like connection, wherein the mechanical link is substituted by a magnetic link. Obviously the permanent magnets 50 and 52 are selected with predetermined magnetic power enough for attaining a good connection of said members 10 and 11, but small enough to prevent damage of the articulator and of the prosthetic work supported thereby and to allow easy detachment of said members by spreading them apart by hand.

Still further, the magnets 50 and 52 are so positioned on the members 10 and 11, respectively, that as said magnets contact upon their faces 51 and 53, respectively, the condyle reproducing end portions 33 of member 11 seat within the glenoid fossa forming recesses 17 of member 10. The magnetic connection of said members 10 and 11 therefore causes the portions 17 and 33 thereof to be relatively set to simulate the anatomic features of the human temporo-mandibular articulation. Since the permanent magnets may be slidably moved relative to each other along their common plane of contact corresponding to the average plane of the mandibular glide, said members 10 and 11 may be relatively moved for reproducing by improvision the actual anatomic lateral and protusive movements of the mandible while the teeth remain in functional contact while the effectively reproduced features of the temporo-mandibular articulation (by end portion 33 in recess 17) confine the sagittal and lateral amplitude of said movements.

Due to the strict adherence of faces 51 and 53 of the magnets 50 and 52, respectively, by magnetic mutual attraction, the two members 10 and 11 are caused to be stable in any desired relative position comprised Within the mandibular glide, in which said members may be set. Such feature may be advantageously used for careful checking of the proper occlusion at any one of anatomically possible positions, of the prosthetic appliance or appliances under work, while the operator is not troubled by the necessity of keeping the articulator in a determined position or required to operate blocking means.

From the above and by a consideration of the accompanying drawing it will be readily understood by those skilled in the art, that I have provided a new and highly advantageous articulator for prosthetic dentistry of the fixed average anatomic type, which is exceptionally simple both in its construction and in its operation, not having pivots, slots, springs or any other mechanical parts which may. be subject to wear and damage and which require to be operated. The articulator of the present invention maybe set at any anatomically functional con-.

dition, the bow members may be fully detached and reset in their functional relative position and relatively secured therein by one simple operation of spacing or closing said members in the desired position, and further that I have provided a novel articulator by which the actual anatomi cal features and mode of operations of the temporomandibular articulation are completely and impressively made apparent in both their anatomical shape and arrangement and relation with the dental problems referring to occlusion.

It will be understood that each of the elements of this new articulator, as described above, or two or more together, may also find useful application in other types of articulators for prosthetic dentistry differing from the type described above.

While I have illustrated and described my invention but in one form of embodiment thereof, and more particularly as embodied in a fixed average anatomic articulator, I do not intend to be limited to the details shown, since various modifications, adaptations and structural changes may be made Without departing in any Way from the spirit of my invention.

For example, while fixed average anatomic articulators built on the concept of assuming a fixed average inclination of 30 of the condylar path in respect to the plane of occlusion are accepted for very accurate prosthetic occlusion in the most of practical cases, different angles of inclination of polar faces 51 and 53 of the magnets may be made use of, where desired.

Further, additive wedge-shaped magnetic or non magnetic elements may vbe easily conceived and provided for insertion thereof between the opposite faces of the magnets to modify the average angle of inclination. A set of such elements may be provided for adapting the articulator to operate according to any angle of a plurality of predetermined angles.

Still further, the typical and advantageous structural simplicity of the described new articulator is maintained if, where-desired, the said articulator would be provided with some additional moving parts to support the magnets and which provide for angular adjustment of said magnets \gith respect to the structure of the respective bow memers.

Without further consideration, the foregoing will so fully reveal the gist of my invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic and specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalents of this invention, as defined in and by the appended claims.

What I claim as new and desire to have protected by Letters Patent is:

1. In an articulator for prosthetic dentistry, of the type including an upper bow mernrber adapted to sustain an upper dental model and an upper denture removably attached to said upper model, a lower bow member adapted to support a lower dental model and a lower denture rernovably attached to said lower model, and permanent magnet means for releasably and slidably connecting said upper bow member to said lower member in any desired occlusive position and for guiding said upper bow member above said lower bow member along a predetermined plane of condylar guidance wherein said dentures remain in functional contact, said magnet means including an upper permanent magnet connected to said upper bow member and having a lower polar plain smooth face situated on the plane and condylar guidance, of a lower permanent magnet connected to said lower bow member and having an upper polar smooth face situated on said plane of condylar guidance, for magnetic detachable and 9 slidable adherence to the. said lower polar face of said upper permanent magnet.

2. In an articulator for prosthetic dentistry, of the type including an upper bow member adapted to sustain an upper dental model and an upper denture removably attached to said upper model, a lower bow member adapted to support a lower dental model and a lower denture removably attached to said lower model, permanent magnet means for releasably and slidably connecting said upper bow member to said lower member in any desired occlusive position and for guiding said upper bow member above said lower member along a predetermined plane of condylar guidance wherein said dentures remain in functional contact within the limits determined by the temporo-mandibular articulation, said magnet means including an upper permanent magnet connected to said upper bow member and having a lower polar plain smooth face situated on said plane of condylar guidance, and a lower permanent magnet connected to said lower bow member and having an upper polar smooth face, situated on said plane of condylar guidance for magnetic detachable and slidable adherence to the said lower polar face of said upper permanent magnet; and means connected to said upper and to said lower bow members for confining the said relative movements in said plane within limits corresponding to the limits determined by the temporo-mandibular articulation.

3. An articulator for prosthetic dentistry, of the fixed average anatomic type, comprising, in combination: an upper bow member having an upper principal fore portion adapted to detachably sustain an upper dental model and an upper prosthetic appliance removably attached thereunder; a lower bow member having a lower principal fore portion adapted to detachably support a lower dental model and a lower prosthetic appliance removably attached thereto, said lower bow member movably supporting said upper member in a desired arrangement wherein the said upper and lower prosthetic appliances remain in occlusive dental functional contact within the positions determined by the plane of condylar guidance; an upper permanent magnet firmly connected to said upper bow member and having a plain and smooth polar lower surface parallel to said plane of condylar guidance; and a lower permanent magnet firmly connected to said lower bow member and having a plain and smooth polar upper surface parallel to said plane of condylar guidance for detachably and slidably adhering to said lower polar surface of said upper magnet as said members are set in said desired arrangement for having said members detachably connected by magnetic attraction while in said desired arrangement.

4. An articulator for prosthetic dentistry, of the fixed average anatomic type, comprising, in combination; an upper bow member adapted to sustain an upper dental model and an upper prosthetic appliance removably attached thereunder; a lower bow member adapted to support a lower dental model and a lower prosthetic appliance removably attached thereto, said lower bow member movably supporting said upper member in a desired arrangement wherein the said upper and lower prosthetic appliances remain in dental occlusive functional contact as determined by the anatomic features of the actual temporo-mandibular articulation; upper magnetic means connected to said upper bow member; lower magnetic means connected to said lower bow member for magnetic detachable and slidable adherence to and against said upper magnetic means as said members are set in said desired arrangement; and portions integral to said upper and to said lower bow members, shaped and positioned to reproduce in true average shape, dimension and relative position the actual osseous maxillar and respectively mandibular structure forming the temporo-mandibular articulation.

5. An articulator for prosthetic dentistry, of the fixed average anatomic type, comprising, in combination; an

upper bow member having an upper principal fore portion adapted to detachably sustain an upper dental model and an upper prosthetic appliance removably attached thereunder; a lower bow member having a lower principal fore portion adapted to detachably support a lower dental model and a lower prosthetic appliance removably attached thereto, said lower bow member movably supporting said upper member in a desired arrangement wherein the said upper and lower prosthetic appliances remain in dental functional contact within the limits determined by the anatomic features of the actual temporomandibular articulation and within the positions determined by the plane of condylar guidance actuated by said articulation; an upper permanent magnet firmly connected to said upper bow member and having a plain and smooth polar lower surface parallel to said plane of condylar guidance; a lower permanent magnet firmly connected to said lower bow member and having a plain and smooth polar upper surface parallel to said plane of condylar guidance for detachably and slidably adhering to said lower polar surface of said upper magnet as said members are set in said desired arrangement for having said members detachably connected by magnetic attraction while in said desired arrangement; and portions integral to said upper and to said lower bow members, shaped and positioned to reproduce in true average shape, dimension and relative position the actual osseous maxillar and respectively mandibular structure forming the temporo-mandibular articulation.

6. An articulator for prosthetic dentistry comprising, in combination: an upper bow member adapted to sustain an upper dental model and an upper prosthetic appliance removably attached thereunder; a lower member adapted to support a lower dental model and a lower prosthetic appliance removably attached thereto, said lower bow member movably supporting said upper member in a desired arrangement wherein the said upper and lower prosthetic appliances remain in dental occlusive functional contact as determined by the anatomic features of the actual temporo-mandibular articulation; upper magnetic means connected to said upper bow member; lower magnetic means connected to said lower bow member, for magnetic detachable and slidable adherence to and against said upper magnetic means as said members are set in said desired arrangement; rearwardly extended symmetrical portions having recessed enlarged ends, integral with the said upper bow member and shaped for reproducing in actual average size and arrangement the side rear portions of the actual osseous maxillar structure comprising the glenoid fossa; upwardly extended symmetrical portions having shaped upper ends, integral with the said lower bow member, shaped for reproducing in actual average size and arrangement the side rear portions of the actual osseous mandibular structure comprising the condyle, and positioned to co-operate with said glenoid fossa reproducing portions to reproduce in actual size, position and performance the said temporo-mandibular articulation.

7. An articulator for prosthetic dentistry comprising, in combination: an upper bow member adapted to detachably sustain an upper dental model and an upper prosthetic appliance removably attached thereunder; a lower bow member adapted to detachably support a lower dental model and a lower prosthetic appliance removably attached thereto, said lower bow member movably supporting said upper member in a desired arrangement wherein the said upper and lower prosthetic appliances remain in occlusive dental functional contact within the positions determined by the plane of condylar guidance; an upper permanent magnet connected to said upper bow member and having a polar lower surface parallel to said plane of condylar guidance; a lower permanent magnet connected to said lower bow member and having a polar upper surface parallel to said plane of condylar guidance for detachably and slidably adhering to said lower polar surfaceof said upper magnet as said members are set in said desired arrangement for having said members detachably connected by magnetic attraction while in said desired arrangement; rearwardly extended symmetrical portions having recessed enlarged ends, integral with the said upper bow member and shaped for reproducing in actual average size and arrangement the side rear portions of the actual osseous maxillary structure comprising the glenoid fossa; upwardly extended symmetrical portions having shaped upper ends, integral with the said lower bow member, shaped for reproducing in actual average size and arrangement the side rear portions of the actual osseous mandibular structure comprising the condyle, and positioned to co-operate with said glenoid fossa reproducing portions to reproduce in actual size, position and performance of condylar guidance the osseous structure actuating the temporo-mandibular articulation.

8. An articulator for prosthetic dentistry, of the fixed average anatomic type, comprising, in combination: an upper bow member having an upper principal fore portion adapted to detachably sustain an upper dental model and an upper prosthetic appliance removably attached thereunder; a lower bow member having a lower principal fore portion adapted to detachably support a lower dental model and a lower prosthetic appliance removably attached thereto, said lower bow member movably supporting said upper member in a desired arrangement wherein the said upper and lower prosthetic appliances remain in dental functional contact within the limits determined by the anatomic features of the actual temporo-mandibular articulation and within the positions determined by the plane of condylar guidance actuated by said articulation; an upper permanent magnet firmly connected to said upper bow member and having a plain and smooth polar lower surface parallel to said plane of condylar guidance; a lower permanent magnet firmly connected to said lower bow member and having a plain and smooth polar upper surface parallel to said plane of condylar guidance for detachably and slidably adhering to said lower polar surface of said upper magnet as said members are set in said desired arrangement for having said members detachably connected by magnetic attraction while in said desired arrangement; rearwardly extended symmetrical portions having recessed enlarged ends, integral with the said upper principal portion of said upper bow member and shaped for reproducing in actual average size and arrangement the side rear portions of the actual osseous maxillar structure comprising the glenoid fossa; upwardly extended symmetrical portions having shaped upper ends, integral with the said lower principal portion of said lower bow member, shaped for reproducing in actual average size and arrangement the side rear portions of the actual osseous mandibular structure comprising the condyle, and positioned to cooperate with said glenoid fossa reproducing portions to reproduce in actual size, position and performance of condylar guidance the said temporo-mandib-ular articulation.

9. An articulator for prosthetic dentistry, including relatively movable upper and lower bow members designed to hold upper and respectively lower prosthetic appliances, and designed to reproduce the relative arrangement of tooth contact of upper and respectively of lower average natural dentitions supported by the natural osseous maxillary and respectively mandibular structures, as defined by the actual temporo-mandibular articulation comprising the glenoid fossa and respectively the condyle; wherein the said upper bow member is provided with two symmetrical rearwardly and sidewardly directed extensions having down-faced, recessed and enlarged end portions shaped for reproducing in actual average size and position the glenoid fossa and the neighbouring maxillary osseous structure; wherein the said lower bow member is provided with two symmetrical rearwardly and upwardly directed extensions having upper end portions shaped for reproducing in actual average size and position the condyle and the neighbouring mandibular osseous structure; wherein the said upper bow member is connected to a first permanent magnet having a lower polar face; and wherein the said lower bow member is connected to a second permanent magnet having an upper polar face positioned to be magnetically attracted against the polar face of said first magnet as said bow members are set in said relative arrange- -rnent of tooth contact.

10. An articulator for prosthetic dentistry, of the fixed average anatomic type and including relatively movable upper and lower bow members designed to hold upper and respectively lower prosthetic appliances, designed to reproduce the relative arrangement of tooth contact in an occlusion plane, and designed to reproduce the relative movements, due to the mandibular glide, of upper and respectively of lower average natural dentitions supported by the natural osseous maxillary and respectively mandibular structures, as defined by the actual condylar guidance due to the anatomic features of the temporo-mandibular articulation comprising the glenoid fossa and respectively the condyle; wherein the said upper bow member is formed by a single shaped piece of transparent plastic material, including a fore principal portion adapted to detachably sustain an upper appliance supporting dental model thereunder, and including two symmetrical rearwardly and sidewardly directed extensions having down-faced, recessed and enlarged end portions, and shaped to reproduce in average actual size'and position the glenoid fossa and the neighbouring maxillar osseous structure; wherein the said lower bow member is formed by a single shaped piece of transparent plastic material, including a lower fore principal portion adapted to alternatively and detachably support either a lower appliance supporting dental model or an additive member having an upper fiat surface positioned to actuate said occlusion plane, and including two symmetrical rearwardly and upwardly directed extensions having upper end portions and shaped to reproduce in actual average size and position the condyle and the neighbouring mandibular osseous structure; wherein the said upper bow member is fixedly connected to a rodshaped first permanent magnet having a lower fiat polar face parallel to the direction of mandibular glide; and wherein the said lower bow member is fixedly connected to a rod-shaped second permanent magnet having an upper flat polar face parallel to the direction of said mandibular glide and positioned to be magnetically attracted towards and in contact against said lower polar face of said first permanent magnet as said bow members are set in said relative arrangement, and designed to be slidably moved in respect to and in contact with said first magnet as said bow members are relatively moved to reproduce the said mandibular glide.

References Cited in the file of this patent UNITED STATES PATENTS 

